In order to take dental impressions, it is well known that dentists use an alginate gel poured into a mold that is positioned around the teeth of a patient. Once the gel has solidified into the mold, the same is extracted from the mouth of the patient, thus obtaining the desired dental impression.
With regard to the above, alginate gel is obtained from a mixture of water and alginate powder. It is important mentioning that said powder is very fine and is obtained from marine algae as its main raw material. When dental alginate is mixed with water, a gelification reaction occurs between such substances.
When a dentist or his assistant is preparing a mixture of water and alginate, he must be careful of exactly measuring predetermined amounts of such ingredients in order to form a gel having the desired consistency, which allows the dentist to work easily with the gel. Therefore, alginate producers recommend and indicate in their products the exact amounts of water and alginate to be measured in order to prepare adequate mixtures. In fact, most of the alginate producers include in their packages two measuring devices, one for alginate and one for water, with the purpose of measuring such required amounts. The measuring devices are containers, spoons, etc., most of them having printed marks that indicate the dentist the amount of water or alginate that is measured.
Moreover, some alginate producers often include kits for preparing mixtures; one of said kits is disclosed in U.S. Pat. No. 5,709,467, incorporated herein by reference. Particularly, the invention of this patent is a mixing pouch, in which water and alginate are mixed by hand. In a preferred embodiment of the invention disclosed in said patent, a predetermined amount of alginate is previously included into the pouch, therefore a dentist only have to add water into the pouch and mix the content. However, this document does not mention how to exactly measure the required amounts of alginate. In addition, if a package of alginate is provided with a set of pouches, the volume of the package will be increased.
Measuring water and alginate is not an easy and fast work for dentists, since there are some cares that must be taken, for example, due to the tendency of alginate powder to form lumps, the alginate package must be shaken prior to extract the alginate with the corresponding measuring device. Alginate has hydrophilic properties, therefore, it is recommended to store the packages of alginate in dry places in order to maintain the properties of this substance.
With regard to the above, if a dentist uses lumps of alginate, it is very probable that he will measure an incorrect amount of alginate and the resulting mixture will have a poor performance for taking dental impressions. This problem also occurs when a dentist uses amounts of water distinct to those recommended by the alginate producer.
In addition, when dentists handle alginate powder, there are cleaning problems on the working area, inasmuch as alginate powder is very volatile and tends to float in the air. This problem is more frequent when an excess of alginate is extracted from the package using such measuring devices, inasmuch as some part of the excess will be inevitably deposited on the working area when the dentist tries to return the excess to the package. On the other hand, dentists must be careful of avoiding alginate to be contaminated by dust or substances contained in the air when a package is opened.
From the foregoing, it can be observed that a dentist or his assistant has to spend much time in measuring the required amounts of water and alginate and they have to adequately handle alginate. In the prior art, there is a lack of devices or machines that automatic measuring the substances used for taking dental impressions. In other words, nowadays, there is not a machine for dosing water and alginate, which covers all the dentist requirements in this measuring and handling activity.